1. Field
This disclosure relates to a negative active material for a rechargeable lithium battery, a method of preparing the same, and a rechargeable lithium battery including the same.
2. Description of the Related Technology
Batteries generate electric power by using electrochemical reaction materials (referred to hereinafter simply as an “active material”) for a positive electrode and a negative electrode. Rechargeable lithium batteries generate electrical energy from changes of chemical potential during the intercalation/deintercalation of lithium ions at the positive and negative electrodes.
Rechargeable lithium batteries use materials that reversibly intercalate or deintercalate lithium ions during charge and discharge reactions for both positive and negative active materials, and also contain an organic electrolyte or a polymer electrolyte between the positive electrode and the negative electrode.
Composite metal oxides have been used in positive active materials in rechargeable lithium batteries. Examples include composite metal oxides such as LiCoO2, LiMn2O4, LiNiO2, LiNi1-xCoxO2 (0<x<1), LiMnO2, and the like have been used.
For a negative active material of a rechargeable lithium battery, various carbon-based materials such as artificial graphite, natural graphite, and hard carbon, all of which can intercalate and deintercalate lithium ions, have been used. Among the carbon-based materials, graphite has a low discharge potential of about −0.2V relative to lithium. Thus, a battery using graphite as a negative active material has a high discharge potential ranging from about 3.6V and has excellent energy density. The graphite guarantees a long cycle life for a battery due to its outstanding reversibility. However, graphite negative active material has a low density of about 1.6 g/cc and consequently has a low capacity in terms of energy density per unit volume.
Therefore, high-capacity negative active materials that can replace graphite active material are desirable. The embodiments discussed herein address this problem and provide additional advantages as well.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the prior art already know in this country to a person of ordinary skill in the art.